Filament switch



May15,192s. 1,669,437" S. A. YOUNG FILAMENT SWITCH Filed June 1. 1925INVENTOR,

Simeon Ayounj A TTORNEY.

l www@ Patented May 15, 1928.

i UNITED STAT-Es Lhftfid' MffifiirrQFP'ICE.w

smsen A. YOUNG, oF Los ANGELES, eALironNIA.

rrLAMEN'r SWITCH.

My invention relates to electric switches and more particularly to aspecial form of electric switch designed for use in connection withradio receiving sets.

The main object of my invention is to provide an electric switchsuitable for mounting on the instrument panel of a radio receiving set,so that it may be connectedr in the battery circuit, supplying currentto the lilaments of the vacuum tubes.

Another object is to provide a filament switch of the characterdescribed which may be adjusted for panels of different thicknesses;which can be easily mounted, and which is simple and inexpensive to makeand which is convenient to operate.

Other objects and advantages will appear hereinafter and while I showherewith and will describe a preferred form of construction, I desire tobe understood that I do not limit my invention to such preferred formbut that various changes and adaptations may be made therein withoutdeparting from the spirit of my invention as hereinafter claimed.

Referring to the drawings which accompany this specification and form apart thereof:

Fig. 1 is a fragmentary view of a front panel in a receiving set casewith a filament switch embodyingthe principles Vof my in vention mountedthereon.

Fig. 2 is a rear View of the switch shown in Fig. l in its openposition, and a partial diagram of a filament circuit illustrating theconnection of the switch therein.

Fig. 3 is a similar View to that shown in Fig. 2, showing the switch inits closed position.

Fig. 4 is an enlarged sectional view of the switch taken on line 1 -1 ofFig. 1.

Fig. 5 is an enlarged lower-end view of theswitch shown in Fig. 1, asseen in a section taken through the panel approximately on the line 5-5of that figure.

The various parts of my filament switch as designated by the referencenumerals, are as follows:

A metal mounting plate 10, with a screwthreaded aperture 11 near one endof its ends, has a transverse insulating plate 12 and an insulatingblock 13 secured. to the other end thereof by rivets 14e extendingtherethrough, the insulating plate coinciding in length with the widthof the mounting plate and the insulating block being sufri- Appn'anonined. June '1, 1925. serial No. $3,933.]

ciently shorter torform` angles 15 between them at their ends. Leafsprings 16 and 17 are held in these angles by fastening screws 18 whichextend through them into the ends of block 13, so that they arecompletelyinsulated from each other and from mounting plate 10. Thelength of the springs' is such that they extend `beyond the insulatingblock and form lugs 19 in which apertures 20 are made to receive thebattery circuit conductors. `Their other ends extend parallel to themounting plate somewhat beyond aperture 11, spring 16 being slightlylonger than spring 17 and both having their ends bent inwardly to formright angled hooks 21, the purpose of which will presently appear.

An externally screw-threaded sleeve 22 with a hexagonal head 28, madeintegral therewith, extends through aperture 11 and engages the threadsthereof to hold mounti by a set screw 32, so that it turns with thestub-shaft, there being an insulated handle 33 fixed to head 28 of theshaft by which it may be turned. Cam 29 is so adjusted that one of itspoints 34; is inv continuous contact with Spring 16 while its otherpoint 35 makes or breaks contact with spring 17 when the shaft isturned. e

Sleeve 22 and stub-shaft 27, are made of a length to permitadjustmentfor use with panels of different thicknesses and the manner ofattaching cam 29 to the shaft also provides for such adjustment, besidesallowing for the adjustmentL of handle 33 in any preferred positionabout the axis of the shaft.

The operation of my switch is clearly shown in Figs. 1, 2, and 3. It isconnected in one side of the A-hattery circuit, preferably between thenegative pole of the battery 36 and the return conductor 37 common tofilaments 38 of one or more vacuum tubes. When the switch is in its openposition, as shown in Fig. 2, contact point 34: of cam 29 engages hook21 of spring 16 while contact point 35 falls short of spring 17 farenough to leave a gap 89 therebetween. Cam 29 is held in this positionby the combined action of the hook vand spring', the former preventingthe cam from turning in one direction and the pressure of the latterpren venting the turning thereof in the other direction. When the switchis turned into its closed position, as shown in Fig. 3, lcontact point35 engages spring 17 and springs 16 and 17 both yield outwardly untilpoint 35 comes into engagement with hook 21 of spring 17 Cam 29 is heldin this closed position by the combined action of hook 2l and bothsprings, the `pressure of which acts on vopposite sides of the shaftaxis to hold the cam from turning into its open position. In its closedposition the'cam serves as Aa conductor between the two springs, andcauses current to ow through the filaments of .the vacuum tubes.

Having thus illustrated and described my invention I claim: v

In an electric switch, a pair of contacts consisting of leaf springshaving substantially straight body portions and end hooks, a block lofinsulating material to opposite sides .of which the body portions ofsaid leaf springs are securedin a flatwise manner, and a manuallyrotatable switch element having contact points, one of said points beingcontinuously in engagement with one of said springs and the other pointbeing :movable into and-out of engagement with-the other of saidsprings, said hooks limiting the amount of rotation of said manuallyoperable element, said springs having sufficient resiliency betweentheir free ends and their points of attachment to said block to holdthem at all times in proper operative relation to saidfrotatable switchelement.

SIMEON A. YOUNG.

